The invention concerns a tire valve for the rim of a pneumatic tire on a vehicle having a valve body which includes a longitudinal bore and which comprises rigid, in particular metal material with a valve base which is arranged at one end and which has an annular shoulder projecting radially from the valve body.
Such a tire valve can be found in the present applicants"" EP 0 751 017 B1. The valve body of that tire valve comprises an anodised aluminum alloy, it includes a valve insert and it terminates at a spacing relative to the rim at a valve cap. By virtue of a male screwthread, the valve body can receive a screw sleeve, with the rim being clamped between the screw sleeve and the annular shoulder of the valve base formed on the valve body. The tire valve terminates within the rim in a signal housing which has two base elements for fitting on to the rim bed and for adjustable mounting in the assembled condition. The connecting element between the tire valve and the signal housing is a hollow screw which engages into the valve bore of the tire valve which bears with the annular shoulder against a seat in the signal housing, the head of the screw bearing against the side, which is remote from the valve, of a longitudinal wall of the signal housing, the screw engaging through the longitudinal wall with clearance.
In consideration of that state of the art the inventor set himself the object of so improving a tire valve of the kind set forth in the opening part of this specification that it can be more easily handled and can be more universally employed.
That object is attained by the teaching of the independent claim; the appendant claims set forth advantageous developments. The scope of the invention also embraces all combinations of at least two of the features disclosed in the description, the drawing and/or the claims.
In accordance with the invention the valve body is connected to a coaxial valve sleevexe2x80x94preferably of rigid materialxe2x80x94by an intermediate tube of elastic material, and the valve sleeve is inclinable limitedly in relation to the longitudinal axis of the tire valve. That elastic intermediate tube bears at one end clampingly against a hollow shank of the valve body and at the other end surrounds as a central valve component the end region of the valve sleeve, which is disposed in adjacent spaced relationship.
Those features afford a tire valve which is elastic bendable approximately in its axial central regionxe2x80x94and also restorablexe2x80x94and which in accordance with the stated object is considerably better to handle than a tire valve which is rigid in itself.
The valve body which here determines only a part of the valve length is of such a configuration that the mouth of the longitudinal bore of the hollow shank is arranged at a head tube which delimits thereon a radial annular shoulder towards the axis; this valve body is therefore provided with at least two annular shoulders of which onexe2x80x94at the valve basexe2x80x94projects from the hollow shank while the other forms a return configuration in the cross-section of the hollow shank. For that purpose it has been found desirable that, in the region of the mouth opening of the hollow shank, at least one external ridge or bead projects radially from the hollow shankxe2x80x94at a spacing relative to the adjacent internal annular shoulderxe2x80x94, the external bead forming an outwardly protruding support for the intermediate tube.
For the purposes of fixing the intermediate tube the valve body is to be at least partially surrounded by a screw sleeve which extends at a radial gap spacing relative to the external bead of the hollow shank and forms therewith a paired clamping configuration for the intermediate tube. It is possible for that screw sleeve to be connected in force-locking relationship to a region of the intermediate tube, which region bears against the screw sleeve at the inside thereof, the screw sleeve being for example glued in position orxe2x80x94preferablyxe2x80x94subjected to a vulcanising procedure; in this embodiment it is attached to the unit consisting of the valve sleeve and the intermediate tube and is to be removed therewith from the valve body without any problem.
In accordance with a further feature of the invention the end region of the intermediate tube, which is associated with the valve sleeve, is preferably vulcanised to the adjacent sleeve surface. In addition, in the region of an annular edge of the intermediate tube, an external ring should bear against the intermediate tube at the inside thereof, which external ring is formed on the valve sleevexe2x80x94to be provided at the free end thereof with a valve capxe2x80x94and is also fixedly connected to the intermediate tube by a vulcanising procedure.
A ring of elastic material which is arranged between the annular shoulder of the valve base and the oppositely disposed lower edge of the screw sleeve has proven to be advantageous, as a support element for the rim; that ring can be deformed by the pressing pressure of the screw sleeve and can be caused to bear against an edge of the opening in the rim. For the purposes of improved mounting and pressure distribution at the elastic ring, an annular disk of rigid material can also be inserted between the elastic ring and the lower edge of the screw sleeve.
The tire valve according to the invention is for example about 60 mm in length and the free spacing between the valve body and the valve sleeve should approximately correspond to between a sixth and a seventh of that valve length. For that purpose it has been found desirable for the length of the intermediate tube to be so selected as to approximately correspond to the length of the valve body or the length of the valve sleeve; the length of the valve body should be somewhat greater than the length of the sleeve.
In order to impart good stability to the tire valve in accordance with a further feature of the invention the length of the overlap region of the intermediate tube and the screw sleeve should approximately correspond to between a third and a quarter of the length of the valve body and/or the length of the overlap region of the intermediate tube and the valve sleeve should approximately correspond to between a third and a half of the length of the valve sleeve.
The tire valve designed in accordance with the invention has proven in internal tests conducted by the applicants to be extremely handleable with a high degree of stability.